Grade of non-muscle-invasive bladder cancer (NMIBC) is an important prognostic factor for progression. Currently, two World Health Organization (WHO) classification systems (WHO1973, categories: grade 1-3, and WHO2004 categories: papillary urothelial neoplasm of low malignant potential [PUNLMP], low-grade [LG], high-grade [HG] carcinoma) are used.
To ask the European Association of Urology (EAU) and International Society of Urological Pathology (ISUP) members regarding their current practice and preferences of grading systems.
A web-based, anonymous questionnaire with ten questions on grading of NMIBC was created. The members of EAU and ISUP were invited to complete an online survey by the end of 2021. Thirteen experts had previously answered the same questions.
The submitted answers from 214 ISUP members, 191 EAU members, and 13 experts were analyzed.
Currently, 53% use only the WHO2004 system and 40% use both systems. According to most respondents, PUNLMP is a rare diagnosis with management similar to Ta-LG carcinoma. The majority (72%) would consider reverting back to WHO1973 if grading criteria were more detailed. Separate reporting of WHO1973-G3 within WHO2004-HG would influence clinical decisions for Ta and/or T1 tumors according the majority (55%). Most respondents preferred a two-tier (41%) or a three-tier (41%) grading system. The current WHO2004 grading system is supported by a minority (20%), whereas nearly half (48%) supported a hybrid three- or four-tier grading system composed of both WHO1973 and WHO2004. The survey results of the experts were comparable with ISUP and EAU respondents.
Both the WHO1973 and the WHO2004 grading system are still widely used. Even though opinions on the future of bladder cancer grading were strongly divided, there was limited support for WHO1973 and WHO2004 in their current formats, while the hybrid (three-tier) grading system with LG, HG-G2, and HG-G3 as categories could be considered the most promising alternative.
Grading of non-muscle-invasive bladder cancer (NMIBC) is a matter of ongoing debate and lacks international consensus. We surveyed urologists and pathologists of European Association of Urology and International Society of Urological Pathology on their preferences regarding NMIBC grading to generate a multidisciplinary dialogue. Both the "old" World Health Organization (WHO) 1973 and the "new" WHO2004 grading schemes are still used widely. However, continuation of both the WHO1973 and the WHO2004 system showed limited support, while a hybrid grading system composed of both the WHO1973 and the WHO2004 classification system may be considered a promising alternative.
European urology open science. 2023 May 10*** epublish ***
Irene J Beijert, Liang Cheng, Fredrik Liedberg, Karin Plass, Sean R Williamson, Paolo Gontero, Maria J Ribal, Marko Babjuk, Peter C Black, Ashish M Kamat, Ferran Algaba, David M Berman, Arndt Hartmann, Alexandra Masson-Lecomte, Morgan Rouprêt, Antonio Lopez-Beltran, Hemamali Samaratunga, Shahrokh F Shariat, A Hugh Mostafid, Murali Varma, Steven Shen, Maximilian Burger, Toyonori Tsuzuki, Joan Palou, Eva M Compérat, Richard J Sylvester, Theo H van der Kwast, Bas W G van Rhijn, Michelle R Downes
Department of Surgical Oncology (Urology), Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands., Department of Pathology and Laboratory Medicine, Brown University Warren Alpert Medical School, Lifespan Academic Medical Center and Legorreta Cancer Center at Brown University, Providence, RI, USA., Department of Translational Medicine, Lund University, Malmö, Sweden., European Association of Urology, Non-Muscle Invasive Bladder Cancer Guidelines Panel, Arnhem, The Netherlands., Department of Pathology, Cleveland Clinic, Cleveland, OH, USA., European Association of Urology, Guidelines Office Board, Arnhem, The Netherlands., Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada., Department of Urology, University of Texas, MD Anderson Cancer Center, Houston, TX, USA., Department of Pathology, Fundació Puigvert, Universitat Autónoma de Barcelona, Barcelona, Spain., Kingston Health Sciences Centre, Queen's University, Kingston, ON, Canada., Institute of Pathology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany., Department of Morphological Sciences, University of Cordoba Medical School, Cordoba, Spain., Department of Pathology, Aquesta Uropathology and University of Queensland, Brisbane, Australia., Department of Cellular Pathology, University Hospital of Wales, Cardiff, UK., Department of Pathology Genomic Medicine, Houston Methodist Hospital and Weill Cornell Medical College, Houston, TX, USA., Department of Surgical Pathology, Aichi Medical University Hospital, Nagakute, Japan., Laboratory Medicine Program, University Health Network, Princess Margaret Cancer Center, University of Toronto, Toronto, Canada., Division of Anatomic Pathology, Precision Diagnostics and Therapeutics Program, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.